The 200 million-dollar (£154m) estate of a 91-year-old descendant of Hawaiian royalty is at the centre of a power-of-attorney battle between her lawyer and her long-time partner.

Campbell Estate heiress Abigail Kawananakoa suffered an acute stroke in June and on July 24 her lawyer, James Wright, was granted control of her estate by a state probate judge.

But Kawananakoa's partner Veronica Worth disputes this claim, saying the heiress is still capable of making financial decisions.

Her lawyer, Michael Rudy, said a renowned panel of three psychological experts would be hired to examine Ms Kawananakoa, and the first has already found her mentally competent.

Another evaluation is being processed, he said, while a third is being arranged.

Ms Worth, who possesses Ms Kawananakoa's health care power of attorney, has been Ms Kawananakoa's partner for more than 20 years.

Mr Rudy said Ms Worth's only aim was to put Ms Kawananakoa back in charge of her finances, but Mr Wright says he fears there is a greater money grab in play that could seriously affect Ms Kawananakoa's plan to set up a charity on behalf of the Native Hawaiian people.

Mr Wright's lawyer Frank Kanemitsu said in court documents that since the stroke Ms Kawananakoa was "unable to meet essential requirements of physical health, safety, self-care or financial matters", even with assistance.

Mr Wright said: "Ms Kawananakoa and her legacy need the protection of the court.

"I have represented her for nearly 20 years and spoke to her three hours before the stroke.